PROJECT SUMMARY/ABSTRACT We are requesting support for a study of brain sensorimotor abnormalities in childhood onset psychotic illnesses. Motor deficits are consistently found in psychotic patient populations and have also been identified as among a few promising early childhood risk factors for psychosis. We will employ a combination of neurobehavioral methods with non-invasive neuroimaging using magnetoencephalography (MEG) and structural magnetic resonance imaging (MRI). Eighty young participants with either childhood onset psychotic bipolar disorder (N=40) or schizophrenia (N=40) will be compared to age and gender matched comparison subjects (N=40) without personal or family history of psychotic and/or bipolar mood disorders. Our general perspective on motor coordination deficits is two-fold. First, we propose that a failure in inter-hemispheric motor inhibition results in failures to properly coordinate timing signals in bimanual coordination. Second, we believe that a failure in feed-forward efferent copy mechanisms from motor to somatosensory cortex results in improper perceptual feedback during patient's own movements. Our long term goals for this research are to refine the neurobiology of motor deficits in psychotic disorders, develop biomarkers for future family-based studies of genetic risk and evaluate neurobiological differences between schizophreniform and mood-related psychotic illnesses. Some of these biomarkers should be associated with psychosis per se and others with more disorder specific clinical manifestations. Such knowledge could a) contribute to earlier and more accurate diagnosis, b) lead to improved treatment planning at onset of illness, c) assist with more accurate estimate of illness trajectory and prognosis, d) aid in the development of possible new endophenotypic markers for psychosis, and e) form the basis for future family studies relating to genetic vs. developmental contributions to these disorders.